Usability Hinders mPARK-ers in Edinburgh

mPARK, a new innovative system of paying for parking meter tickets from your mobile was launched on 31st October 2003 in Edinburgh. The system uses 266 new solar-powered pay-and-display machines around the city centre. User Vision set out to discover how intuitive and easy to use the new system is.

Welcome, but sorry!

mPark -ChrisThe system of being able to pay for your parking ticket without having to worry about whether or not you have change or enough change is a useful and appealing option. Keen to try out the new service, we went to the nearest mPARK parking meter. The instructions are concise and clearly presented on a white label with illustrations located on the front of the parking meter. First you press the yellow button to activate the machine and to display the ‘pay & display’ meter number. Then you dial the phone number on your mobile. You are pleasantly greeted by a recorded voice message saying “Welcome to mPARK. If you have not pressed the yellow button, please do so now.” Soon after this, we discover that we are not able to carry on using the system because we have not registered for it. The voice message continued to state, “I’m sorry but you are not currently registered to use this service, to register now please hold the line or go to” It is likely that a lot of users will not choose to take up the offer for registering now (over the phone), due to expensive peak call rates. Further inspection of the instructions and the meter itself did not reveal any prompts to register. The web address for mPARK is only mentioned on a small sticker stuck to the side of the parking meter that can be missed very easily. So before you can use the system, users must first register on the mPARK website.

In attempting to register for the service, several unpleasant encounters were experienced. First off it’s difficult to find out exactly where you can and should register for mPARK. Short of going to mPARK’s website, there are few direct links to registration, not even from the website of ItsMobile, the company that created mPARK. Edinburgh City Council’s website currently gives information about mPARK, with a single link pointing users to mPARK’s website to register or to find out more information. Apart from an mPARK sticker on the side of the new solar powered ‘pay & display’ machines, you might never know that you have to go to their site first. This suggests that they need to raise the profile for mPARK in Edinburgh. Currently if you do not frequent the council’s website you will not really know about it.

We are pleased to see that mPARK’s website adopts a minimalist approach to it’s design. The colours used are kept to a minimum and main navigation areas are easily identified. On the home page our attention is quickly drawn to a few references to “click here”, 3 of them to be exact. If the links are represented clearly then the user doesn’t need to be told to “click here”, not withstanding the very nature of “click here” lacks contextual meaning. It tells the users to “Just click on the Registration link to register for the service. Registration is completely free”. Why not make the word ‘Registration’ a link rather than forcing users to search around the page for it? Likewise, telling users to “Check out the cities within the UK where the mPARK service is up and running” is a poor instruction, which would benefit by making ‘check out the cities’ a link to the Edinburgh page, which currently, is the only city in UK where the service is up and running. On the right hand side, you have a section called “payment options”. Clicking on ‘Visa’, ‘MasterCard’ or ‘FastPay’ takes you to their respective sites without telling the user that they will leave mPARK’s site. The expectation could be that by clicking on ‘VISA’, for example, you will set up your payment by VISA.

mPARK’s inaccessibility

Accessibility of the site is poor in general. You might reason that those who are blind or have impaired vision do not need to or cannot drive, and so it doesn’t matter whether this site does not use relative sized fonts, but that misses the point of web accessibility and is bad practice. Furthermore, many of the images lack tags, and the tariffs table is not accessible because it is lacking the correct HTML mark up to allow screen reading software to interpret it as a data table. Many of the links are black and not underlined, the same as normal text colour, and users will have to ‘mine sweep’ the page with their mouse to find links. Along with that, the roll over colour of links is a very pale grey, which gives poor contrast from the white background. The “Service Demo” link does not have the roll over feedback of the other navigation. Edinburgh City Council’s own site is generally quite accessible and they clearly have put effort in. Does the Council really want to be associated with such a non-accessible site?


Clicking on the “Edinburgh” link under right hand side’s “mPARK Locations” section takes you to a page showing some information about the mPARK scheme in Edinburgh without introducing or providing a link in the page (e.g. ‘See where you can park in Edinburgh’) to the map showing where you can use mPARK. Although there is a navigation button in the left hand side of this page to “Where can I park” many will not see it because it is newly introduced on that page. It is also not clear if the navigation button refers to ‘Where can I park’ in Edinburgh or ‘Where can I park’ as in what cities mPARK is available.

The map itself is poorly represented. There are 2 maps – when you click on the first map a second “more detailed” map pops up in a new window. It is impossible to read the street names on the first map which has blue dots scattered around the city, but there is no key showing what these blue dots represent. Do these blue dots tell you where you can use mPARK? But some of them lie outside the area outlined in red, which is mPARK coverage. Or do they represent all parking areas around the city? The second “more detailed” map that supposedly gives you more detail does not have these blue dots, so it remains a mystery.

Pay for call and pay for park

The tariffs page is not very helpful. It shows that the costs for using mPARK are the same is if you would be paying by cash. Considering that mPARK users still have to pay for the cost of the call from their mobile phone, they might like to know, before registering, that there is no economical incentive for using the new payment option. The main problem for the tariffs page is that it refers to “Zones,” i.e. 1A, 2, 3, etc. Users will appreciate knowing what or where these zones refer to in the city and there is no link to a map to show these.

On the “Instructions” page you are told that it is important to have caller ID enabled on your phone and it says, “For more information on caller id, please read the Frequently asked Questions.” It would be useful to make these last words a link to FAQ, which is on the left hand side of the site home page but no longer available on the instructions page. When you use mPARK parking meters you need to have caller ID enabled on your mobile phone so that the system can identify you. If you do not have caller ID switched on then the pre-recorded instructions will state this and hang up the call.

The service demo opens up in a new window (the page even states “The service demonstration has launched in a new window”). But if the user has left the previous map page open and behind the main page, the demo will open there – unlikely ever to be discovered by an average web user so it appears to be a broken link. The demo is in Flash without text equivalent, which is another accessibility problem and fails to serve those who do not have Flash player installed. It is also self paced with unclearly labeled steps. If a user missed or did not understand a point, they might think they can’t go back, pause or skip through to review it. First time users will not know that you can go back and review individual instructions as a review page is only presented at the end of the demo. Users may think they have to start again or they will give up with the demo. There is no link to instructions or quick user guide for the service from the Flash demo. Rather than being forced to remember a series of seemingly complicated actions shown in the demo, the user should be able to print out the quick guide making the service less daunting to use.

mPARK – No spaces

Completing the registration form was relatively difficult. There is no contextual help or formatting instructions for entering username and password, clarifying illegal characters, minimum and maximum lengths. The fields are also inflexible, such that when you enter your phone or credit card number with spaces, it produced a confusing error message saying “Please enter a valid phone number.” Error handling is poor. Similarly entering “O’Brien” (as a mother’s maiden name) was not accepted as valid input due to the apostrophe. At this point you are able to edit the greeting message that you will see on the mPARK parking meter. A confusing question was also encountered at the end of registration – “Select this box if you do not wish to be able to use other mobile phone payment services in the future.” Users will not choose to select this if they are not fully aware of what it implies. For example, does it mean that it will prevent users from using other services that use mobile phone payment?

Feedback on registration is immediate. You are sent an SMS with your username, password and phone number to call when using the service, but no instructions for use. The first screen you see after logging on is not welcoming or friendly. You are presented with a list of recent transactions which, not surprisingly, is empty since you have only just registered. For first time users, this page could be better used by providing a clear welcome message and an overview of the services in the secure area. The “Family & friends” page is also poor, in that, there is no information included in that page, instead you have to click on “About family & friends” to find out what it’s for.

Try mPARK again

mPARK interfaceAfter registering successfully we go back to try and get our ‘pay & display’ ticket. First we press the yellow button to get the parking meter’s ID number, and then dial the telephone number from the mobile and using caller ID, the system works out who is calling. After you’ve entered the machine number into your mobile you are shown your personal greeting message on the parking meter’s display, e.g. “Good Morning Mr Rourke.” This is friendly and users will find this reassuring. PIN numbers are only required for motorists using NatWest’s FastPay system to pay. Anyone paying using their credit card or, in future, mobile phone bills, will simply have to phone the main number and enter the machine number which is displayed in front of them. That’s a lot of different numbers to enter, simply in order to get a ticket out of the parking meter. I suspect that a lot of people would rather just stick some coins in the slot, rather than have to go through some overly-lengthy process with their mobile. It takes quite a long time to display the machine number after pressing the yellow button and once you’ve called the number, you have to listen to the entire recorded voice information menu option list before you key in the machine number. Good IVR (Interactive Voice Response) systems will allow you to override the voice prompts before the finish reading the entire menu – this one doesn’t.

It is good that the system gives a prompt for whether or not you want to be reminded 10 minutes before your ticket expires via SMS (reminder texts cost 20p). However, you are only given a couple of seconds to decide whether you want that or not. The biggest drawback of the system is that you are only allowed to increase your parking duration by 1 hour increments. If you pay by coins you can go up by 15 minute increments. Unfortunately, there is no way of decrementing your parking duration, which is highly restrictive. There is no provision for error recovery. Once you press the blue button, there is no going back, except for pressing the cancel button and start again. A user will expect the system to cycle through the increments, rather than being stuck at the maximum duration of 2 hours when all they wanted is perhaps a half hour or 1 and a half hours.


This innovative payment method offers convenience by allowing motorists to ‘pay & display’ without the worries of having no change or not enough change. As long as you have a mobile phone with you, and you are registered, you can use mPARK anywhere in the city. It can even send you a text to remind you that your ticket will expire in 10 minutes. Unfortunately this innovative use of technology is limited by an often difficult user journey from start to finish.

In short the mPARK user experience suffers from a number of usability short comings. These include the following:

  • Poor map information about where it can be used
  • Inflexible forms for registration
  • Self paced, Flash service demo
  • Opening new browsers without informing the user
  • Confusing text and prompts on the website
  • No room given for error recovery on mPARK parking meters

The website also has several accessibility problems such as missing Alt tags, fixed size fonts, data tables improperly marked up for screen reader use and reliance on inaccessible Flash for a key part of the site content.

Many of these issues could be identified by observing people using the system for real. A short series of usability tests covering the entire end to end process could reveal these obstacles, most of which are easily fixed.

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This article was written by Chris Rourke. Chris is the Managing Director of User Vision, a usability and accessibility consultancy that helps clients gain a competitive advantage through improved ease of use.

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